Robert H Pietrzak

The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia

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Publications (137)563.69 Total impact

  • Jack Tsai, Julia M Whealin, Robert H Pietrzak
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    ABSTRACT: Objectives. We (1) compared use of various health services nationally between Asian American and Pacific Islander (AA/PI) veterans and veterans of other racial/ethnic groups and (2) specifically compared perceived barriers and stigma related to mental health services. Methods. Using bivariate and multivariable statistics, we analyzed a population-weighted sample of 8315 veterans from the 2010 National Survey of Veterans and a random sample of 567 recent veterans from Hawaii. Results. A total of 1.5% of veterans were AA/PI compared with 0.4% a decade ago. Compared with other veterans, AA/PI veterans reported higher socioeconomic status and better mental health, although these findings may be specific to AA veterans. Adjusting for sociodemographic and health differences, we found no differences in health service use or perceived barriers or stigma related to mental health services. Conclusions. AA/PIs are a small but fast-growing racial/ethnic group within the veteran population that deserves attention. Although veteran status may be protective against some barriers to mental health care found in the general AA/PI population, efforts to reduce barriers to health care among veterans should be continued.
    American journal of public health. 09/2014; 104 Suppl 4:S538-47.
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    ABSTRACT: Background: The detection of early Alzheimer's disease (AD) can rely on subjective and informant reports of cognitive impairment. However, relationships between subjective cognitive impairment, objectively measured cognitive function, and amyloid-β (Aβ) biomarkers remain unclear. Objective: To determine the extent to which impairment or decline in subjective and informant rated cognitive impairment was associated with memory in healthy older adults with high Aβ. Methods: Healthy older adults (n = 289) enrolled in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study were studied at baseline. Pittsburgh Compound B was used to determine Aβ status at baseline. At baseline and 18 months assessments, subjective memory impairment was assessed using the Memory Complaint Questionnaire and the Short Form of the Informant Questionnaire on Cognitive Decline in the Elderly. Cognition was measured using the Cogstate Brief Battery. Results: At baseline, there were no differences between low and high Aβ groups in subjective or informant-rated cognitive impairment, depressive and anxiety symptoms, or cognitive function. Longitudinal analyses showed moderate decline in learning and working memory over the 18 months in the high Aβ group. However there was no change over time in subjective or informant-rated cognitive impairment, depressive and anxiety symptoms, or cognition in either Aβ group. Conclusions: Although healthy older adults with high Aβ levels show decline in learning and working memory over 18 months, subjective or informant ratings of cognitive impairment do not change over the same period suggesting subjective cognitive impairment may have limited utility for the very early identification of AD.
    Journal of Alzheimer's disease: JAD 08/2014; · 4.17 Impact Factor
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    ABSTRACT: Trauma-focused cognitive behavioral treatments are known to be effective for posttraumatic stress disorder (PTSD) in adults. However, evidence for effective treatments for older persons with PTSD, particularly elderly war trauma survivors, is scarce. In an open trial, 30 survivors of World War II aged 65 to 85 years (mean, 71.73 years; SD, 4.8; n = 17 women) with PTSD symptoms were treated with a Web-based, therapist-assisted cognitive-behavioral/narrative therapy for 6 weeks. Intent-to-treat analyses revealed a significant decrease in PTSD severity scores (Cohen's d = 0.43) and significant improvements on secondary clinical outcomes of quality of life, self-efficacy, and posttraumatic growth from pretreatment to posttreatment. All improvements were maintained at a 3-month follow-up. The attrition rate was low (13.3%), with participants who completed the trial reporting high working alliance and treatment satisfaction. Results of this study suggest that integrative testimonial therapy is a well accepted and potentially effective treatment for older war trauma survivors experiencing PTSD symptoms.
    The Journal of nervous and mental disease. 08/2014;
  • Becca R Levy, Corey E Pilver, Robert H Pietrzak
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    ABSTRACT: Older military veterans are at greater risk for psychiatric disorders than same-aged non-veterans. However, little is known about factors that may protect older veterans from developing these disorders. We considered whether an association exists between the potentially stress-reducing factor of resistance to negative age stereotypes and lower prevalence of the following outcomes among older veterans: suicidal ideation, anxiety, and posttraumatic stress disorder (PTSD). Participants consisted of 2031 veterans, aged 55 or older, who were drawn from the National Health and Resilience in Veterans Study, a nationally representative survey of American veterans. The prevalence of all three outcomes was found to be significantly lower among participants who fully resisted negative age stereotypes, compared to those who fully accepted them: suicidal ideation, 5.0% vs. 30.1%; anxiety, 3.6% vs. 34.9%; and PTSD, 2.0% vs. 18.5%, respectively. The associations followed a graded linear pattern and persisted after adjustment for relevant covariates, including age, combat experience, personality, and physical health. These findings suggest that developing resistance to negative age stereotypes could provide older individuals with a path to greater mental health.
    Social science & medicine (1982). 07/2014; 119C:170-174.
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    ABSTRACT: Background There is increasing recognition that, in addition to negative psychological consequences of trauma such as post-traumatic stress disorder (PTSD), some individuals may develop post-traumatic growth (PTG) following such experiences. To date, however, data regarding the prevalence, correlates and functional significance of PTG in population-based samples are lacking. Method Data were analysed from the National Health and Resilience in Veterans Study, a contemporary, nationally representative survey of 3157 US veterans. Veterans completed a survey containing measures of sociodemographic, military, health and psychosocial characteristics, and the Posttraumatic Growth Inventory-Short Form. Results We found that 50.1% of all veterans and 72.0% of veterans who screened positive for PTSD reported at least ‘moderate’ PTG in relation to their worst traumatic event. An inverted U-shaped relationship was found to best explain the relationship between PTSD symptoms and PTG. Among veterans with PTSD, those with PTSD reported better mental functioning and general health than those without PTG. Experiencing a life-threatening illness or injury and re-experiencing symptoms were most strongly associated with PTG. In multivariable analysis, greater social connectedness, intrinsic religiosity and purpose in life were independently associated with greater PTG. Conclusions PTG is prevalent among US veterans, particularly among those who screen positive for PTSD. These results suggest that there may be a ‘positive legacy’ of trauma that has functional significance for veterans. They further suggest that interventions geared toward helping trauma-exposed US veterans process their re-experiencing symptoms, and to develop greater social connections, sense of purpose and intrinsic religiosity may help promote PTG in this population.
    Psychological Medicine 06/2014; · 5.59 Impact Factor
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    ABSTRACT: Boxing requires agility and manual dexterity, which is associated with fast reflexes and reaction time. This study evaluated the relation between reaction times on cognitive tasks and competition outcomes in boxers. The design was a prospective cohort study. Participants were collegiate amateur boxers who won at least one bout in a single elimination tournament. Optimal pre-participation performance using a computerized cognitive assessment tool (CCAT, Axon Sports) and no significant deterioration in cognitive performance within 24 hours post-bout was required to compete in future bouts. Winners were assumed to be motivated to perform optimally on testing. Performance on speed and accuracy measures were compared in winning and non-winning boxers. Pre-competition minutes of sparring and tournament seedings were recorded. There were 96 eligible boxers who won at least one of 160 bouts. The mean age was 21.3 (SD 1.9) years (range 18.5-29.7). A significant improvement in mean reaction times as a function of advancement in the boxing tournament was observed. The 18 winning boxers who advanced to the finals had significantly faster mean reaction times at the baseline assessment before the competition began (speed composite z-score F(1,94)=4.14, P<0.05, effect size 0.54). Winners also had more sparring experience (Mann-Whitney U=302.5, P<0.001) and higher pre-competition rankings (Mann-Whitney U=288.5, P<0.001). In highly motivated amateur boxers, finalists performed significantly faster than those who failed to reach the finals on measures of pre-competition reaction time. These findings suggest that winners of boxing tournaments might be predicted using pre-competition measures of processing speed.
    The Journal of sports medicine and physical fitness 06/2014; 54(3):340-6. · 0.73 Impact Factor
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    ABSTRACT: Sexual trauma during military service is increasingly recognized as a substantial public health problem and is associated with detrimental effects on veteran mental health. In this study, we examined associations between childhood trauma, military sexual trauma (MST), combat exposure, and military-related posttraumatic stress symptomatology (PTSS) in the Women Veterans Cohort Study (WVCS), a community-based sample of veterans who served in the recent conflicts in Iraq and Afghanistan.
    The Journal of clinical psychiatry. 06/2014; 75(6):637-643.
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    ABSTRACT: OBJECTIVES: Suicide in recent veterans is an international concern. An association between mental disorders and suicide has been established, but less information is available about an association between physical health problems and suicide among veterans. This study extends this area of inquiry by examining the relationship of both physical and mental health problems with suicidal ideation in a representative national sample of Canadian veterans. METHODS: Subjects were a stratified random sample of 2,658 veterans who had been released from the Canadian Armed Forces Regular Force during 1998-2007 and had participated in the 2010 Survey on Transition to Civilian Life. Associations between physical and mental health and past-year suicidal ideation were explored in multivariable regression models using three measures of physical and mental health. RESULTS: The prevalence of suicidal ideation was 5.8% (95% confidence interval [CI]: 5.0%-6.8%). After adjustment for covariates, ideation was associated with gastrointestinal disorders (adjusted odds ratio [AOR] 1.66, CI: 1.03-2.65), depression or anxiety (AOR 5.06, CI: 2.97-8.62) and mood disorders (AOR 2.91, CI: 1.67-5.07); number of physical (AOR 1.22, CI: 1.05-1.42) and mental conditions (AOR 2.32, CI: 2.01-2.68); and SF-12 Health Survey physical health (AOR 0.98, CI: 0.96-0.99 for each 1 point increase) and mental health (AOR 0.88, CI: 0.87-0.89). CONCLUSIONS: Physical health was independently associated with suicidal ideation after adjustment for mental health status and socio-demographic characteristics. The findings underscore the importance of considering physical health in population-based suicide prevention efforts and in mitigating suicide risk in individual veterans.
    Canadian journal of public health. Revue canadienne de santé publique 05/2014; 105(2):e109-115. · 1.02 Impact Factor
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    ABSTRACT: Attentional bias to threat is a key endophenotype that contributes to the chronicity of trauma-related psychopathology. However, little is known about the neurobiology of this endophenotype and no known in vivo molecular imaging study has been conducted to evaluate candidate receptor systems that may be implicated in this endophenotype or the phenotypic expression of trauma-related psychopathology, which is comprised of threat (i.e., re-experiencing, avoidance, and hyperarousal) and loss (i.e., emotional numbing, depression/dysphoria, generalized anxiety) symptomatology. Using the radioligand [(11)C]OMAR and positron emission tomography (PET), we evaluated the relationship between in vivo cannabinoid receptor type 1 (CB1) receptor availability in the amygdala, and performance on a dot-probe measure of attentional bias to threat, and clinician interview-based measures of trauma-related psychopathology. The sample was comprised of adults presenting with a broad spectrum of trauma-related psychopathology, ranging from non-trauma-exposed, psychiatrically healthy adults to trauma-exposed adults with severe trauma-related psychopathology. Results revealed that increased CB1 receptor availability in the amygdala was associated with increased attentional bias to threat, as well as increased severity of threat, but not loss, symptomatology; greater peripheral anandamide levels were associated with decreased attentional bias to threat. A mediation analysis further suggested that attentional bias to threat mediated the relationship between CB1 receptor availability in the amygdala and severity of threat symptomatology. These data substantiate a key role for compromised endocannabinoid function in mediating both the endophenotypic and phenotypic expression of threat symptomatology in humans. They further suggest that novel pharmacotherapies that target the CB1 system may provide a more focused, mechanism-based approach to mitigating this core aspect of trauma-related psychopathology.Neuropsychopharmacology accepted article preview online, 13 May 2014; doi:10.1038/npp.2014.110.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 05/2014; · 8.68 Impact Factor
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    ABSTRACT: The aim of the study was to compare the long-term effects of conflict-related sexual violence experienced at the end of World War II (WWII) with non-sexual WWII trauma (e.g., being exposed to shell shock or physical violence). A total of 27 elderly wartime rape survivors were compared to age- and gender-matched control subjects who were drawn from a larger sample of subjects over 70 years of age who had experienced WWII-related trauma. A modified version of the Posttraumatic Diagnostic Scale was used to assess trauma characteristics and posttraumatic stress disorder (PTSD) symptoms and the Brief Symptom Inventory-18 was used to assess current psychopathology. Additionally, measures of posttraumatic growth (Posttraumatic Growth Inventory) and social acknowledgement as a trauma survivor (Social Acknowledgement Questionnaire) were used to assess two mediating variables in post-trauma conditions of rape victims. Women exposed to conflict-related sexual violence reported greater severity of PTSD-related avoidance and hyperarousal symptoms, as well as anxiety, compared with female long-term survivors of non-sexual WWII trauma. The vast majority (80.9 %) of these women also reported severe sexual problems during their lifetimes relative to 19.0 % of women who experienced non-sexual war trauma. Women exposed to conflict-related sexual violence also reported greater posttraumatic growth, but less social acknowledgement as trauma survivors, compared to survivors of non-sexual war trauma. The results were consistent with emerging neurobiological research, which suggests that different traumas may be differentially associated with long-term posttraumatic sequelae in sexual assault survivors than in other survivor groups and highlights the need to treat (or better prevent) deleterious effects of conflict-related sexual violence in current worldwide crisis zones.
    Archives of Sexual Behavior 03/2014; · 3.53 Impact Factor
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    ABSTRACT: Although beta-amyloid, anxiety and depression have been linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data from an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.
    The British journal of psychiatry: the journal of mental science 02/2014; · 6.62 Impact Factor
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    ABSTRACT: There is considerable public and professional concern about the mental health status of veterans deployed to Iraq and Afghanistan as well as how to engage and retain symptomatic veterans in treatment. This study examined demographic, psychiatric, and psychosocial determinants of prospective initiation and retention in mental health services among symptomatic Iraq/Afghanistan veterans. One hundred thirty-seven symptomatic veterans who were referred to mental health screening completed a survey at the time of their first mental health visit. Associations between survey variables and subsequent Veterans Affairs service utilization were evaluated. The most consistent determinants of mental health service initiation and retention were severity of posttraumatic stress disorder (PTSD) and depressive symptoms. Notably, whereas PTSD-related re-experiencing symptoms were independently associated with initiation of mental health treatment, PTSD-related numbing symptoms were independently associated with retention in treatment. Stigma, barriers to care, and beliefs about mental health treatment were not associated with either mental health initiation or retention.
    The Journal of nervous and mental disease 02/2014; 202(2):97-104. · 1.77 Impact Factor
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    ABSTRACT: OBJECTIVE: Cross-sectional genetic association studies have reported equivocal results on the relationship between the brain-derived neurotrophic factor (BDNF) Val66Met and risk of Alzheimer's disease (AD). As AD is a neurodegenerative disease, genetic influences may become clearer from prospective study. We aimed to determine whether BDNF Val66Met polymorphism influences changes in memory performance, hippocampal volume, and Aβ accumulation in adults with amnestic mild cognitive impairment (aMCI) and high Aβ. METHODS: Thirty-four adults with aMCI were recruited from the Australian, Imaging, Biomarkers and Lifestyle (AIBL) Study. Participants underwent PiB-PET and structural MRI neuroimaging, neuropsychological assessments and BDNF genotyping at baseline, 18 month, and 36 month assessments. RESULTS: In individuals with aMCI and high Aβ, Met carriers showed significant and large decline in episodic memory (d = 0.90, p = .020) and hippocampal volume (d = 0.98, p = .035). BDNF Val66Met was unrelated to the rate of Aβ accumulation (d = -0.35, p = .401). CONCLUSIONS: Although preliminary due to the small sample size, results of this study suggest that high Aβ levels and Met carriage may be useful prognostic markers of accelerated decline in episodic memory, and reductions in hippocampal volume in individuals in the prodromal or MCI stage of AD.
    PLoS ONE 01/2014; 9(1):e86498. · 3.73 Impact Factor
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    ABSTRACT: Associate learning is fundamental to the acquisition of knowledge and plays a critical role in the everyday functioning of the developing child, though the developmental course is still unclear. This study investigated the development of visual associate learning in 125 school age children using the Continuous Paired Associate Learning task. As hypothesized, younger children made more errors than older children across all memory loads and evidenced decreased learning efficiency as memory load increased. Results suggest that age-related differences in performance largely reflect continued development of executive function in the context of relatively developed memory processes.
    PLoS ONE 01/2014; 9(7):e101750. · 3.73 Impact Factor
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    ABSTRACT: Introduction Recent confirmatory factor analytic studies of the dimensional structure of posttraumatic stress disorder (PTSD) suggest that this disorder may be best characterized by five symptom dimensions—re-experiencing, avoidance, numbing, dysphoric arousal, and anxious arousal. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation in PTSD and has been attributed to enhanced glucocorticoid responsiveness. However, little is known about how altered HPA-axis function is related to this contemporary phenotypic model of PTSD. Methods We compared morning plasma cortisol levels of drug-free civilian adults with PTSD (N = 29) to trauma-exposed (TC; N = 12) and non-trauma-exposed healthy controls (HC; N = 23). We then examined the relation between cortisol levels and a contemporary 5-factor ‘dysphoric arousal’ model of PTSD symptoms among individuals with PTSD. Results After adjustment for white race/ethnicity, education, lifetime alcohol use disorder, and current smoking status, the PTSD (Cohen's d = 1.1) and TC (Cohen's d = 1.3) groups had significantly lower cortisol levels than the HC group; cortisol levels did not differ between the TC and PTSD groups. Except for age (r = −.46), none of the other demographic, trauma-related, or clinical variables, including lifetime mood/anxiety disorder and severity of current depressive and anxiety symptoms, were associated with cortisol levels. In a stepwise linear regression analysis, age (β = −.44) and severity of emotional numbing symptoms (β = −.35) were independently associated with cortisol levels in the PTSD group; none of the other PTSD symptom clusters or depression symptoms were significant. Post hoc analyses revealed that severity of the emotional numbing symptom of restricted range of affect (i.e., unable to have loving feelings) was independently related to cortisol levels (β = −.35). Conclusion These results suggest that trauma-exposed civilian adults with and without PTSD have significantly lower cortisol levels compared to healthy, non-trauma-exposed adults. They further suggest that low cortisol levels among adults with PTSD may be specifically linked to emotional numbing symptomatology that is unique to the PTSD phenotype and unrelated to depressive symptoms.
    Psychoneuroendocrinology 01/2014; 39:88–93. · 5.14 Impact Factor
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    ABSTRACT: High amyloid has been associated with substantial episodic memory decline over 18 and 36 months in healthy older adults and individuals with mild cognitive impairment. However, the nature and magnitude of amyloid-related memory and non-memory change from the preclinical to the clinical stages of Alzheimer's disease has not been evaluated over the same time interval. Healthy older adults (n = 320), individuals with mild cognitive impairment (n = 57) and individuals with Alzheimer's disease (n = 36) enrolled in the Australian Imaging, Biomarkers and Lifestyle study underwent at least one positron emission tomography neuroimaging scan for amyloid. Cognitive assessments were conducted at baseline, and 18- and 36-month follow-up assessments. Compared with amyloid-negative healthy older adults, amyloid-positive healthy older adults, and amyloid-positive individuals with mild cognitive impairment and Alzheimer's disease showed moderate and equivalent decline in verbal and visual episodic memory over 36 months (d's = 0.47-0.51). Relative to amyloid-negative healthy older adults, amyloid-positive healthy older adults showed no decline in non-memory functions, but amyloid-positive individuals with mild cognitive impairment showed additional moderate decline in language, attention and visuospatial function (d's = 0.47-1.12), and amyloid-positive individuals with Alzheimer's disease showed large decline in all aspects of memory and non-memory function (d's = 0.73-2.28). Amyloid negative individuals with mild cognitive impairment did not show any cognitive decline over 36 months. When non-demented individuals (i.e. healthy older adults and adults with mild cognitive impairment) were further dichotomized, high amyloid-positive non-demented individuals showed a greater rate of decline in episodic memory and language when compared with low amyloid positive non-demented individuals. Memory decline does not plateau with increasing disease severity, and decline in non-memory functions increases in amyloid-positive individuals with mild cognitive impairment and Alzheimer's disease. The combined detection of amyloid positivity and objectively-defined decline in memory are reliable indicators of early Alzheimer's disease, and the detection of decline in non-memory functions in amyloid-positive individuals with mild cognitive impairment may assist in determining the level of disease severity in these individuals. Further, these results suggest that grouping amyloid data into at least two categories of abnormality may be useful in determining the disease risk level in non-demented individuals.
    Brain 01/2014; 137(1):221-231. · 9.92 Impact Factor
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    ABSTRACT: Background Posttraumatic stress disorder (PTSD) is characterized by heterogeneous clusters of re-experiencing, avoidance, numbing, and hyperarousal symptoms. However, data are lacking regarding the predominant, population-based typologies of this disorder, and how they are linked to trauma-related characteristics, psychiatric comorbidities, and health-related quality of life. Methods We used latent class analyses (LCAs) to evaluate predominant typologies of PTSD in a nationally representative sample of 2463 U.S. adults with PTSD. Multinomial logistic regression analyses were then conducted to evaluate trauma-related characteristics, psychiatric comorbidities, and health-related quality of life variables associated with these typologies. Results LCAs revealed three predominant typologies of PTSD—Anxious-Re-experiencing (weighted prevalence=32.2%), Dysphoric (32.8%), and High Symptom (35.0%). Compared to the Dysphoric class, the Anxious-Re-experiencing and High Symptom classes were more likely to report sexual assault, physical assault, and military combat as their worst traumatic events; had an earlier age of onset and longer duration of PTSD; and were more likely to be diagnosed with nicotine dependence and borderline personality disorder, to have attempted suicide, and had poorer physical health-related quality of life (HRQoL). The High Symptom class had increased odds of all disorders, suicide attempts, and the poorest HRQoL. Limitations Diagnoses were based on DSM-IV criteria and cross-sectional analyses preclude examination of how PTSD typologies are temporally related to other variables. Conclusion PTSD in the general U.S. adult population is characterized by three predominant typologies, which are differentially linked to trauma and clinical characteristics. These findings underscore the importance of personalized approaches to the assessment, monitoring, and treatment of PTSD that take into consideration the heterogeneous manifestations of this disorder.
    Journal of Affective Disorders 01/2014; 162:102-106. · 3.30 Impact Factor
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    ABSTRACT: Cognitive decline is an early feature of neurodegenerative conditions. CogState has developed a game-like computerized test battery with demonstrated acceptability, validity, reliability, stability, efficiency and sensitivity to detecting cognitive decline in older people under supervised conditions. This study aimed to evaluate an internet-based version of this test when used remotely and self-administered in a cohort of healthy, community-dwelling older adults aged 55 and above over a 12month period at 1-3 monthly intervals. Test usability and reliability was examined in terms of acceptability, stability and reliability. Of 150 participants (age: 63.6+/-5.6, range 55-83years), 143 (95%) successfully completed a valid baseline test. Of these, 67% completed 3month and 43% 12months of testing. Technical difficulties were reported by 9% of participants. For those participants who completed 12months tests, all tasks showed moderate to high stability and test-retest reliability. This brief computerized test battery was shown to have high acceptability for baseline self-administered testing and moderate to high stability for repeated assessments over 12months. Attrition was high between baseline and 3months. These data suggest that this tool may be useful for high frequency monitoring of cognitive function over 6-12months, and deserves further evaluation.
    Computers in Human Behavior 01/2014; 30:199-205. · 2.27 Impact Factor
  • Biological Psychiatry. 01/2014;
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    ABSTRACT: Background High β-amyloid (Aβ) is associated with faster memory decline in healthy individuals and adults with mild cognitive impairment (MCI). However, longer prospective studies are required to determine if Aβ-related memory decline continues and whether it is associated with increased rate of disease progression. Methods Healthy controls (HCs; n = 177) and adults with MCI (n = 48) underwent neuroimaging for Aβ and cognitive assessment at baseline. Cognition was reassessed 18 and 36 months later. Results Compared with low-Aβ HCs, high-Aβ HC and MCI groups showed moderate decline in episodic and working memory over 36 months. Those with MCI with low Aβ did not show any cognitive decline. Rates of disease progression were increased in the high-Aβ HC and MCI groups. Conclusions In healthy individuals, high Aβ likely indicates that Alzheimer's disease (AD)-related neurodegeneration has begun. Once commenced, the rate of decline in cognitive function remains constant across the preclinical and prodromal stages of AD.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 01/2014; · 14.48 Impact Factor

Publication Stats

1k Citations
563.69 Total Impact Points


  • 2014
    • The Florey Institute of Neuroscience and Mental Health
      Melbourne, Victoria, Australia
    • United States Department of Veterans Affairs
      Bedford, Massachusetts, United States
  • 2009–2014
    • Yale-New Haven Hospital
      • Department of Laboratory Medicine
      New Haven, Connecticut, United States
    • RMIT University
      Melbourne, Victoria, Australia
  • 2013
    • University of Greifswald
      • Department of Psychiatry and Psychotherapy
      Greifswald, Mecklenburg-Vorpommern, Germany
    • University of Manitoba
      Winnipeg, Manitoba, Canada
    • University of Hawaiʻi at Hilo
      Hilo, Hawaii, United States
  • 2009–2013
    • Yale University
      • Department of Psychiatry
      New Haven, Connecticut, United States
  • 2008–2013
    • University of Melbourne
      • • Department of Psychiatry
      • • Melbourne School of Psychological Sciences
      Melbourne, Victoria, Australia
    • Alpert Medical School - Brown University
      • Department of Pediatrics
      Providence, RI, United States
  • 2011
    • Melbourne Institute of Technology
      Melbourne, Victoria, Australia
    • Naval Health Research Center
      • Department of Warfighter Performance
      San Diego, CA, United States
    • Georgetown University
      Washington, Washington, D.C., United States
  • 2006–2011
    • University of Connecticut
      • Department of Psychology
      Storrs, CT, United States
  • 2006–2008
    • UConn Health Center
      • • Division of Behavioral Sciences and Community Health
      • • Department of Psychiatry
      Farmington, CT, United States
  • 2005
    • Colby College
      Waterville, Maine, United States